工厂化水产养殖水质监测系统

工厂化水产养殖的密度高、风险大,养殖对象对pH、溶解氧、温度、氨氮、亚硝酸盐等水质参数的变化敏感,受影响严重,监测水质参数极为重要。本文针对工厂化水产养殖水质监测特点和需求,研发了工厂化水产养殖水质监测系统。分析研究pH、溶解氧、温度、亚硝酸盐等水质参数的阈值,设计水质监测数据无线采集节点和基于Zigbee的无线监测网络,建立水质监测系统软件平台。结果表明,该系统能够实现工厂化水产养殖水质实时监测,保证生产安全,提高水产养殖生产效率。     

中国湖泊、水库水产增养殖技术的进展

中国湖泊可养面积187万公顷,水库可养面积200万公顷,总共占全国内陆可养水面的70％以上。这些水面既是我国渔业在本世纪末年产量达到1800万吨宏伟目标的潜力与后劲之所在,也是“八·五”期间本行业科技攻关的重点。 湖库资源特点与水产增养殖发展概要 (一)湖库资源特点 湖泊可养面积90％相对集中于平原地区,而水库总数的89.4％分布在长江、珠江和黄河三大流域的丘陵地区,具有良好的分布格局。湖泊面积在50平方公里以下的占总数的98％以上,水库中中小型的占99.6％,另有塘坝63万座,中小型水面有利于采取各种集约化措施。     

玻璃钢水槽内大黄鱼养殖环境噪声测量与分析

利用水下声音测量系统,分别记录了开放式圆形玻璃钢水槽内养殖环境噪声和大黄鱼(Larimichthys crocea)摄食过程声音,并进行声压级(sound pressure levels,SPL)计算和频谱特征分析。结果表明:(1)养殖环境噪声SPL约为110.27 d B(d B re:1μPa),包括主频率峰值为100 Hz的养殖工作设备与水槽内壁的低频共振噪声、1 250 Hz的表层水体气泡噪声、1 600~2 500 Hz的曝气石、增氧机、空气压缩机工作噪声;(2)增氧机和曝气关闭时,大黄鱼摄食过程声音SPL约为92.65 d B,高于背景噪声SPL,主要为游泳声音70~500Hz、吞食产生的水体表面搅动与气泡破裂的声音1 000~2 000 Hz、咀嚼颗粒饵料声音2 000~4 500 Hz;(3)增氧机和曝气开启时,背景噪声SPL略高于摄食声音约17.62 d B,且摄食声音无法区别于背景噪声,但并未影响鱼类摄食行为。     

To pool or not to pool? Guidelines for pooling samples for use in surveillance testing of infectious diseases in aquatic animals

Samples from multiple animals may be pooled and tested to reduce costs of surveillance for infectious agents in aquatic animal populations. The primary advantage of pooling is increased population‐level coverage when prevalence is low (<10%) and the number of tests is fixed, because of increased likelihood of including target analyte from at least one infected animal in a tested pool. Important questions and a priori design considerations need to be addressed. Unfortunately, pooling recommendations in disease‐specific chapters of the 2018 OIE Aquatic Manual are incomplete and, except for amphibian chytrid fungus, are not supported by peer‐reviewed research. A systematic review identified only 12 peer‐reviewed aquatic diagnostic accuracy and surveillance studies using pooled samples. No clear patterns for pooling methods and characteristics were evident across reviewed studies, although most authors agreed there is a negative effect on detection. Therefore, our purpose was to review pooling procedures used in published aquatic infectious disease research, present evidence‐based guidelines, and provide simulated data examples for white spot syndrome virus in shrimp. A decision tree of pooling guidelines was developed for use by peer‐reviewed journals and research institutions for the design, statistical analysis and reporting of comparative accuracy studies of individual and pooled tests for surveillance purposes.     

池塘养殖尾水经稻田生态工程净化后的浮游细菌群落特征

为利用稻田生态工程对精养池塘尾水进行循环利用,采用Illumina Mi Seq第二代测序技术比较分析了稻田生态工程进出水中浮游细菌群落结构和多样性差异,以探讨稻田生态工程净化回用水中浮游细菌群落变化对池塘养殖的影响。结果显示,稻田生态工程进出水中优势浮游细菌在门水平上的组成相同,均为蓝细菌门(Cyanobacteria)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、浮霉菌门(Planctomycetes)和拟杆菌门(Bacteroidetes)。但优势门类的相对丰度发生变化,蓝细菌门的相对丰度由进水中的46.72%显著降低至表面流出水中的41.82%和渗流出水中的34.77%;而放线菌门的相对丰度由3.90%增加至表面流出水中的5.65%和渗流出水中的6.45%。属水平上优势浮游细菌组成也相同,但微囊藻属(Microcystis)的相对丰度由0.83%显著降低至渗流出水中的0.46%(P0.05)。另外,稻田生态工程表面流出水中浮游细菌物种丰富度指数(Chao 1)显著提高,渗流出水中Shannon多样性指数显著提高,且Simpson指数显著降低(P0.05)。     

养殖水体中高效氨氮降解菌的分离与鉴定

以(NH4)2SO4为惟一氮源的选择性培养基,从养鱼池水中分离筛选到1株高效氨氮降解菌X2。当NH4 -N初始质量浓度为50 mg/L时,该菌株在24 h内的氨氮降解率>95%,并具有硝酸还原和亚硝酸还原能力。初步鉴定该菌株为巨大芽孢杆菌(Bacillus megaterium)。     

A review of production frontier analysis for aquaculture management

Abstract

This paper examines recent advances in production economics with special reference to efficiency measurement using production frontiers and its implications for aquaculture management. Compared with agriculture and other industries, the use of production frontiers in aquaculture is still very limited. However, in recent years several frontier applications in aquaculture have appeared in the literature, suggesting potential applications of these techniques in aquaculture. A synopsis of stochastic frontier production function model and data envelopment analysis (DEA), the two most popular approaches to efficiency measurement, is presented, followed by a review of recent frontier studies in shrimp, carp and tilapia production. The paper concludes with a brief discussion of future development and prospects of frontier applications for aquaculture management.     

Rainbow trout (Oncorhynchus mykiss,Walbaum ) develop a more robust body shape under organic rearing

Prolonged exposure to captive conditions has led to the development of a rainbow trout ‘farmed’ phenotype, which is different from that of wild trout. Selection for desirable productive traits in hatcheries has resulted in the development of some morphological traits that are maladaptive in nature. The recent development of organic aquaculture, guided by the well‐being of the fish, could potentially produce a new farmed phenotype that would be more adaptive in nature. In this study, rainbow trout reared in intensive and organic farms were compared by means of shape analysis, to detect patterns of shape variation associated with rearing environment. The results of this study highlight a significant effect of the rearing method on rainbow trout shape: organically reared trout showed a higher body profile, in particular in the head and trunk regions, shorter median fins and a deeper caudal peduncle. A combined effect of density and habitat complexity could have contributed to the observed shape differences: in organic rearing systems, lower densities and steady water could increase territoriality and aggressive interactions, promoting body designs more functional in rapid attacks and escapes.     

广西工厂化循环水养殖石斑鱼水质处理效果

通过集成海水养鱼、生化处理、设施工程、环境工程、电器自控和水质监控等技术,建立一套适合广西地区应用的工厂化循环水石斑鱼养殖系统。该养殖系统处理流程为:鱼池→沉淀池→蛋白质分离器→生物滤池→海马齿浮床→紫外杀菌,生物滤池包括A、B、C三个通道,A、B通道均由珊瑚石作为一、二级生物过滤和生化球作为三级过滤,C通道由珊瑚石作为一级过滤和椰子壳碎作为二、三级过滤。结果显示:沉淀池处理可以显著降低鱼池的COD,氨氮、亚硝酸盐氮、硝酸盐氮和磷酸盐的质量浓度(P<0.05);经海马齿浮床系统处理后,硝酸盐氮质量浓度显著低于沉淀池、蛋白质分离器处理池、生物滤池A、B通道(P<0.05);整体上,C通道水质指标略低于A、B通道,但差异不明显(P>0.05)。该研究结果可为广西沿海发展循环水养殖技术以及养殖生产方式转变提供可靠的科学数据和技术参考。     

Immunostimulatory effects of dietary poly‐β‐hydroxybutyrate in European sea bass postlarvae

The stable production of high‐quality fry in marine aquaculture is still hampered by unpredictable mortality caused by infectious diseases during larval rearing. Consequently, the development of new biocontrol agents is crucial for a viable aquaculture industry. The bacterial energy storage compound poly‐β‐hydroxybutyrate (PHB) has been shown to exhibit beneficial properties on aquatic organisms such as enhanced survival, growth, disease resistance and a controlling effect on the gastrointestinal microbiota. However, the effect of PHB on the developing immune system of fish larvae has so far not been investigated. In this study, the effect of feeding PHB‐enriched Artemia nauplii on survival, growth and immune response in European sea bass (Dicentrarchus labrax) postlarvae was examined. Amorphous PHB was administered to 28‐day‐old sea bass postlarvae over a period of 10 days. The survival and growth performance were monitored, and the expression of 29 genes involved in immunity, growth, metabolism and stress‐response was measured. While the expression of the insulin‐like growth factor 1 (igf1), an indicator of relative growth, was upregulated in response to feeding PHB, the larval survival and growth performance remained unaffected. After 10 days of PHB treatment, the expression of the antimicrobial peptides dicentracin (dic) and hepcidin (hep) as well as mhc class IIa and mhc class IIb was elevated in the PHB fed postlarvae. This indicates that PHB is capable of stimulating the immune system of fish early life stages, which may be the cause of the increased resistance to diseases and robustness observed in previous studies.